This invention relates to an apparatus for advancing a mining machine comprised of a multiplicity of units for use in an underground mine. More particularly, the present invention relates to such an apparatus wherein a unit of the mining machine comprises a hydraulic unit with a pump and reservoir connected by flexible hoses to a number of hydraulic motors for driving common reduction gearing connected to a toothed drive wheel that is, in turn, engaged with a rack extending in the direction of movement for the mining machine. The hydraulic motors, reduction gearing and toothed drive wheel being received in a winch casing that extends around the toothed rack.
As disclosed in U.S. application Ser. No. 366,151, filed Apr. 7, 1982, now U.S. Pat. No. 4,451,090, drive mechanisms on a mining machine are guided along a toothed rack extending lengthwise of the direction of movement for the mining machine. Each drive mechanism includes at least one drive wheel to engage the teeth of the rack and a hydraulic motor connected to the drive wheel either directly or by way of a transmission. A hydraulic pump on the mining machine is connected by supply lines for hydraulic fluid to the hydraulic motor. The drive wheel, the hydraulic motor or a plurality of hydraulic motors, if used, and possibly the pump and drive motor therefor are disposed on their own carriage or slide which bears on and is guided on the rack. The carriage or slide forms an advancing unit which is separate from the mining machine and extends below at least parts of the rack to insure satisfactory engagement between the drive wheel and the rack. One or more rack-mounted advancing units is disposed between runners on the same side of the mining machine or instead of runners, only advancing units are connected to the body of the mining machine, i.e., to its frame, and serve as runners. Other advancing units situated between these advancing units or runners bear only on the advancing units or runners situated in front thereof in the direction of machine travel. The advancing units which are connected to the runners on the machine are also connected to the adjacent advancing unit or units. This construction and arrangement enables the advancing units to be fitted to a mining machine which is already in use or to provide a mining machine during the actual assembly with the necessary drive power for mining operations at a particular place where the machine is to be used. The advancing mechanisms of this type have the advantage that they can be adapted accurately to the run of the rack even when the advancing unit is not serving as runners or disposed very near a mechanism which serves as a runner. Engagement between a drive wheel and the rack is, therefore, always insured. Consequently, the advancing mechanism can transmit full driving power to the rack for moving the mining machine with the required power at the intended mining site.